One-Pot Two-Step Synthesis of Isochromene-Fused CF3-Substituted Pyrazoles

Abstract

An efficient one-pot, two step method for fusing two biologically active motifs, CF3-substituted pyrazoles and isochromenes, was developed. Selective O-benzylation of CF3-substituted pyrazolones and subsequent Pd-catalyzed direct C–H arylation generate a fused tricycle. For the synthesized compounds through-space 13C–19F spin–spin coupling was revealed. In addition, the synthesis of three thioisochromene analogues, and one isocoumarin derivative, was accomplished.